Leaders of Burma's ethnic Karen minority are appealing for international help against what they describe as increasingly fierce government attacks.

In a formal request Thursday, leaders of the Karen National Union urge the United Nations and the world's democratic countries to bring increased pressure on the Burmese government of President Thein Sein.

In particular, they say the government should be pressured to stop sending troops into battle against the minorities, to seek a political solution to the country's ethnic conflicts and to allow humanitarian organizations to help those affected by the fighting.

The KNU also urges the international community to seek ways to protect the security and rights of the minorities, including the Kachin and Shan peoples as well as the Karen.

A longstanding cease-fire between the government and minorities broke down when the ethnic armies refused to join a government border force, and Burmese troops went on the offensive this year against Kachin and Shan strongholds.

The KNU says more than 20,000 people have been forced to flee for their lives and that numerous human rights violations have been committed, including rape, forced labor and the use of children as human shields.

The organization says the ethnic minorities are ready for dialogue with the government, but that a letter to the president in July has been answered only with increasingly fierce attacks.